Empowering Insights – Glaucoma Symptoms, Types, Treatment, and Surgery

What is Glaucoma?

Glaucoma is a group of eye conditions that damage the optic nerve, crucial for transmitting visual information from the eye to the brain. It’s often associated with increased pressure within the eye, known as intraocular pressure (IOP). However, it can also occur with normal or even low IOP. If left untreated, it can lead to irreversible vision loss and blindness. In the US, blindness ranks as the third most feared health issue, following cancer and cardiac attacks. Regrettably, many individuals remain asymptomatic with glaucoma until a later stage of the disease.

Causes of Glaucoma

Your eye continuously produces a fluid called aqueous humor. Ideally, as new fluid enters the eye, an equal amount should drain out through a region called the drainage angle. This maintains stable intraocular pressure. However, if the drainage angle malfunctions, fluid accumulation occurs, leading to increased pressure inside the eye, which can damage the optic nerve.

When small nerve fibers start to deteriorate, blind spots can form in your vision. Sometimes, people don’t notice these blind spots until many fibers are damaged. If all the fibers die, it can cause blindness.

Types of Glaucoma

There are different types of glaucoma, but the two main types are:

• Primary Open-Angle Glaucoma: It is one of the most prevalent forms of glaucoma, which is typically what people are talking about when they mention glaucoma. In open-angle glaucoma, eye drainage components fail to work properly, causing a slow increase in eye pressure over time.

• Angle-closure glaucoma (also called “closed-angle” or “narrow-angle glaucoma”): In this type, the iris bulges partially or completely, obstructing the drainage angle. It occurs when the drainage space between the iris and cornea narrows, leading to inadequate drainage and sudden pressure buildup within the eye.

Other types include

• Normal tension glaucoma (where optic nerve damage occurs even with normal IOP).
• Congenital glaucoma (present at birth).
• Secondary glaucoma (which is caused by other eye conditions or systemic diseases).

Symptoms of Glaucoma

It progresses slowly often with symptoms that go unnoticed until significant vision
loss occurs. However, symptoms may vary depending on the type and stage of glaucoma.

Open-Angle Glaucoma

• Gradual loss of peripheral vision
• Tunnel vision is usually seen in advanced cases
• Patchy blind spots that are seen in the peripheral or central vision
• Difficulty seeing and adjusting in low light conditions.

Angle-Closure Glaucoma

It is an eye emergency. Here are seven early signs of an impending attack of angle-closure glaucoma. It’s necessary for those experiencing these symptoms to seek immediate evaluation by their ophthalmologist.

• Sudden and severe eye pain.
• Blurred or cloudy vision.
• Halos around lights.
• Redness in the eye.
• Nausea and vomiting.
• Headaches.
• Sudden loss of vision.

Risk Factors of Glaucoma

Glaucoma can affect anyone, but certain factors can increase the risk of developing the
condition. These risk factors include:

• Age:  Over 60 years of age and Hispanic/Latino or African American population above 40 years.

• Family history: Family history of glaucoma, particularly if a parent or sibling has glaucoma.

• Ethnicity: African American, Latino, Asian, or Scandinavian descent

• Medical Conditions: Some medical conditions are known to increase the risk of developing glaucoma. These conditions include diabetes, hypertension, and cardiovascular diseases. A history of eye injuries or surgeries can also raise the risk.

• Thin Corneas: Individuals with thin corneas may have an increased risk of developing glaucoma. Corneal thickness can affect intraocular pressure measurements and influence the risk of glaucoma progression.

• High Myopia (Severe Nearsightedness): Severe nearsightedness is linked with an increased risk of glaucoma, particularly angle-closure glaucoma.

• Use of Corticosteroids: Long-term use of corticosteroid medications, such as eye drops, pills, inhalers, or injections, can increase the risk of developing secondary glaucoma.

Diagnosis of Glaucoma

Diagnosing glaucoma involves a comprehensive eye examination conducted by an ophthalmologist. The process typically includes several key components. But all of these may not be used for one person.

• Tonometry: This test measures your IOP, a crucial risk factor for glaucoma. Various techniques are used to measure IOP, such as applanation tonometry, non-contact tonometry (air puff), or handheld tonometry devices.

• Ophthalmoscopy: During ophthalmoscopy, your doctor will examine the optic nerve at the back of the eye to assess its appearance and look for any signs of damage or abnormalities characteristic of glaucoma. This examination may involve dilating the pupils to visualize the optic nerve head better.

• Gonioscopy: Gonioscopy is a procedure used to assess the drainage angle of the eye, which is crucial for determining the type of glaucoma. It involves using a special lens to visualize the structures in the anterior chamber angle and evaluate the drainage pathways.

• Visual Field Testing: Visual field testing, or perimetry, assesses your peripheral vision’s full horizontal and vertical range. This test helps detect any visual field loss caused by glaucoma. Automated visual field testing methods, such as Humphrey Field Analyzers are commonly used.

• Optical Coherence Tomography (OCT): OCT is a non-invasive imaging technique used to assess the thickness of the retinal nerve fiber layer (RNFL) and visualize the structure of the optic nerve head. It provides detailed, cross-sectional images of the optic nerve and retina, aiding in the early detection and monitoring of glaucoma progression.

• Pachymetry: Pachymetry is a procedure to measure the thickness of the cornea, which can influence intraocular pressure measurements. Central corneal thickness is an important factor in assessing the risk of glaucoma and interpreting intraocular pressure readings accurately.

Treatment of Glaucoma

If you have glaucoma, you should get treatment as soon as possible. While treatment cannot restore lost vision, it can prevent further loss from occurring. Therapeutic modalities for glaucoma are pharmaceuticals (often eye drops), laser therapy, and surgery.

1. Medications for Glaucoma

Prescription eye drops are the most common treatment for glaucoma. These drops help reduce the pressure in the eye and prevent damage to the optic nerve. While glaucoma medications are important for preserving vision, they can also cause side effects.

• Prostaglandin analogs: Prostaglandin analogs are commonly prescribed as first-line therapy for glaucoma due to their efficacy and once-daily dosing convenience. They work by increasing the outflow of aqueous humor through the uveoscleral pathway, thereby reducing intraocular pressure. Common examples include latanoprost, bimatoprost, and travoprost.

• Beta-Blockers: Beta-blockers reduce intraocular pressure by decreasing the production of aqueous humor. They work by blocking beta-adrenergic receptors in the ciliary body, thereby reducing the secretion of aqueous humor. Commonly prescribed beta-blockers for glaucoma include timolol, levobunolol, and betaxolol.

• Alpha Agonists: Alpha agonists reduce intraocular pressure by decreasing aqueous humor production and increasing its outflow. They work by stimulating alpha-adrenergic receptors in the ciliary body to reduce aqueous humor production and constrict blood vessels in the eye to increase fluid drainage. Examples of alpha agonists used in glaucoma treatment include brimonidine and apraclonidine.

• Carbonic Anhydrase Inhibitors (CAIs): CAIs reduce intraocular pressure by inhibiting the enzyme carbonic anhydrase, which is involved in the pathway of producing aqueous humor. By blocking this enzyme, CAIs decrease aqueous humor production, leading to a reduction in intraocular pressure.CAIs can be administered orally or as eye drops, and examples include dorzolamide and brinzolamide.

• Rho Kinase Inhibitors: Rho kinase inhibitors are a newer class of medications used to lower intraocular pressure in glaucoma. They increase the outflow of aqueous humor through the trabecular meshwork, the primary drainage pathway in the eye. Netarsudil is an example of a rho kinase inhibitor approved for treating glaucoma.

2. Laser Therapy for Glaucoma

Laser procedures can effectively lower intraocular pressure and reduce the risk of glaucoma progression. Types of laser therapy used in glaucoma treatment include:

• Selective Laser Trabeculoplasty (SLT): This procedure helps improve drainage of aqueous humor by targeting specific cells in the eye’s drainage angle.

• Laser Peripheral Iridotomy (LPI): LPI is commonly used to treat narrow-angle glaucoma. This procedure makes a small hole in the iris to improve fluid drainage.

3. Glaucoma Surgery

Surgical intervention may be necessary when medications and laser therapy are insufficient to control intraocular pressure. Surgical options for glaucoma include:

• Trabeculectomy: In this procedure, a small opening is created in the sclera to allow fluid to drain out, reducing intraocular pressure.

• Glaucoma Drainage Devices: These small implants are placed inside your eye to drain excess fluid and reduce intraocular pressure.

• Minimally Invasive Glaucoma Surgery (MIGS): MIGS procedures are less invasive than traditional glaucoma surgeries and aim to improve aqueous humor outflow to lower intraocular pressure.

4. Combination Therapy

Sometimes, a single treatment may not be helpful. Medications, laser therapy, and surgery may be recommended to achieve optimal intraocular pressure control and preserve vision.

5. Lifestyle Modifications

Certain lifestyle changes, such as maintaining a healthy weight, avoiding smoking, managing systemic health conditions like diabetes and hypertension, and practicing stress-reducing techniques, may help in managing glaucoma and preventing further vision loss.

Marijuana for glaucoma

You might have heard about numerous treatments that are promoted for treating glaucoma, including marijuana/ CBD, stem cells, herbal medicines, and supplements. Currently, marijuana isn’t recommended for treating glaucoma due to its short-lived effects, side effects, and insufficient evidence showing it alters the course of the condition. Before starting, you should discuss any additional treatments with your doctor, as they are not part of standard glaucoma care and may interfere with your current treatment.

What to expect after glaucoma surgery?

Glaucoma surgery, like any other procedure, may cause temporary swelling and pain in the
eye. Additional hazards include cataract formation, corneal problems, low eye pressure, and possibly vision loss. But these have become rare these days. Your doctor will prescribe eye drops to help with your swelling and infections. You need to use the eye drops for several weeks. These drops differ from other glaucoma treatments you may be taking. During your rehabilitation, you may need to avoid some activities, such as carrying heavy things, for 2 to 4 weeks. Once you start taking medications for glaucoma, your ophthalmologist will schedule regular check-ups for you, typically every 3–6 months, although the frequency may vary based on your specific treatment requirements.

4 Tips For Using Eye Drops Correctly

1. To administer eye drops correctly, tilt your head back and pull down your lower
   eyelid to create a pocket, then squeeze a drop into the pocket and close your eye while gently pressing on the tear duct for a minute.
2. If you need to use different types of drops, wait at least 5 minutes between each application.
3. When applying eye drops, wash your hands well to prevent infection.
4. Do not touch your hands, eyes, or eyelids with the tip of the bottle.

Prevention of Glaucoma

Here are some strategies for preventing glaucoma:

• Regular Eye Exams: Routine eye exams are essential for early detection and treatment of glaucoma. Adults should undergo comprehensive eye examinations at least once every two years or more frequently, as your eye doctor recommends.

• Monitor intra-ocular pressure: Regular monitoring of intra-ocular pressure, especially for individuals with a family history of glaucoma or other risk factors like diabetes, can help detect elevated pressure and prompt timely intervention.

• Maintain a Healthy Lifestyle: Adopting a healthy lifestyle, including regular exercise and a balanced diet rich in fruits and vegetables, can contribute to overall eye health. Some studies suggest that physical activity may help lower intraocular pressure.

• Avoid Smoking: Smoking has been linked to an increased risk of developing glaucoma and may exacerbate the condition in individuals already diagnosed with it. Quitting smoking can help reduce the risk of glaucoma and prevent further damage to the optic nerve.

Questions to ask your Doctor

1. What type of glaucoma do I have?
2. What changes should I expect in my vision, both currently and in the future?
3. Are there any activities or habits that should be avoided?
4. Are there any genetic implications or family members who should also be screened for glaucoma?
5. Are there any alternative therapies that could help manage glaucoma symptoms alongside traditional treatments?

References

• http://What Is Glaucoma? Symptoms, Causes, Diagnosis, Treatment – American Academy of Ophthalmology (aao.org)
• http://Glaucoma Surgery | National Eye Institute (nih.gov)
• http://Treating Glaucoma | glaucoma.org
• http://Glaucoma – NHS (www.nhs.uk)
• http://Primary Congenital Glaucoma – StatPearls – NCBI Bookshelf (nih.gov)
• http://Glaucoma – The International Agency for the Prevention of Blindness (iapb.org)
• http://Don’t Let Glaucoma Steal Your Sight! | CDC
• http://Talk With Your Doctor About Glaucoma guide (nih.gov)
• http://Primary Congenital Glaucoma – StatPearls – NCBI Bookshelf (nih.gov)